1. Field of the Invention
The present invention relates generally to a method of making a wall structure that comprises a polyurethane foam backing and the wall structure fabricated by such a method.
2. Background Information
Spray polyurethane foam insulation may be used within the cavity of a building assembly or on the exterior side of external sheathing. Foam insulation within the cavity is most common and can act as an air barrier in addition to insulation. When foam insulation is applied within the cavity, an external weather resistive barrier is applied to the outside of the external sheathing. Additionally, a vapor retarder may or may not be used within the wall assembly.
When foam insulation is applied to the outside of the external sheathing, the foam (closed cell in particular) acts as the weather resistive barrier, an air barrier, a moisture vapor retarder, and as insulation. In either case, a permanent external sheathing is used as a substrate upon which to apply the foam.